Gravity type sanding valve

Abstract

The invention relates to the technical field of rail transit braking, in particular to a gravity type sanding valve which comprises a main valve body, the main valve body is provided with a sand inlet, a sand channel assembly, a sand outlet head, an air inlet assembly, an air channel assembly and a sand blowing assembly, and the air inlet assembly comprises an air inlet body, a main air inlet connector and a sand outlet tuyere seat. The sand outlet tuyere seat is detachably arranged on the air inlet body, and a sand blowing assembly is arranged on the sand outlet tuyere seat and comprises a mounting seat, a needle rod, an elastic piece and a sand outlet tuyere. The sand blowing assembly is modularly designed, and the needle rod is pressed to be inserted into the air duct of the sand outlet tuyere to dredge the sand blowing assembly, so that the effect of quick and effective cleaning can be achieved, and the sanding efficiency can be greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of rail transit braking, and in particular to a gravity-type sand spreading valve. Background Art

[0002] The sand-spreading valve is installed on the sand box of the rail vehicle. It uses the compressed air inside the vehicle as the power source to spray sand between the wheel and rail to improve its adhesion, prevent the wheel from slipping and idling, and ensure the safe operation of the vehicle.

[0003] The existing sand spreading valves are designed with two downward air nozzles, one in front and one in the back, which eject airflows to lift and blow out the sand. However, during use, the air nozzles may be blocked by sand particles due to contact with the sand particles, resulting in sand spreading failure. In addition, the airflow directly carries the sand particles to wear the internal sand cavity, and the cavity surface is at risk of being blown apart. When the existing sand spreading valve is at the specified low value, the sand particles blown out are parabolically ejected onto the rail surface, rather than being directly ejected between the wedge angles of the rail and the wheelset, resulting in low sand spreading efficiency. Although sand spreading technology has been continuously improved, the above problems have not been fundamentally solved, resulting in potential driving safety hazards.

[0004] In summary, there is an urgent need for a gravity-type sand-spreading valve with high sand-spreading efficiency, adjustable sand-spreading amount and meeting sand-spreading requirements to solve the problems existing in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a gravity-type sand-spreading valve with high sand-spreading efficiency, adjustable sand-spreading amount and meeting the sand-spreading requirements. The specific technical scheme is as follows:

[0006] A gravity-type sand spreading valve comprises a main valve body, wherein the main valve body is provided with a sand inlet, a sand channel assembly, a sand outlet head, an air inlet assembly, an air channel assembly and a sand blowing assembly;

[0007] The sand channel assembly comprises a first sand channel, a second sand channel and a third sand channel which are connected in sequence, one end of the first sand channel is connected to a sand inlet, the other end of the first sand channel is connected to an inlet of a third sand channel arranged in a sand outlet head through the second sand channel, and the outlet of the third sand channel is connected to a sand outlet in the sand outlet head; a sand outlet is provided at the bottom of the first sand channel;

[0008] The air inlet assembly comprises an air inlet body, a total air inlet joint and a sand outlet nozzle seat arranged on the air inlet body; the sand outlet nozzle seat is a columnar structure with a hollow channel and the sand outlet nozzle seat is detachably arranged on the air inlet body; a sand blowing assembly is arranged on the sand outlet nozzle seat, and the sand blowing assembly comprises a needle rod, an elastic member and a sand outlet nozzle, and the sand outlet nozzle is arranged on the sand outlet nozzle seat to provide power for blowing out sand particles in the sand outlet head; the needle rod is inserted into the hollow channel and is movably arranged relative to the sand outlet nozzle through the elastic member, and the air outlet on the sand outlet nozzle is cleaned by controlling the movement of the needle rod;

[0009] The air duct assembly includes a first air duct and a second air duct. The first air duct is connected to the main air inlet joint and the third sand channel in the sand outlet head, and is used to blow out the sand in the sand outlet head; the second air duct is connected to the main air inlet joint and the second sand channel, and is used to blow the sand in the second sand channel into the third sand channel.

[0010] Preferably, the air inlet body is provided with a tapered mounting hole which is wider at the top and narrower at the bottom, and an internal thread is provided in the tapered mounting hole; the sand discharge nozzle seat is a tapered body matching the tapered mounting hole, and an external thread matching the internal thread is provided on the outer wall of the tapered body.

[0011] Preferably, the sand-discharging component also includes an elastic member mounting seat and a pressing seat, and the sand-discharging nozzle is installed at the bottom end of the sand-discharging nozzle seat; the needle rod is inserted into the hollow channel in the sand-discharging nozzle seat until the end face of the sand-discharging nozzle, and the front end of the needle rod close to the sand-discharging nozzle is needle-shaped, and its outer diameter is smaller than the air outlet on the sand-discharging nozzle; the elastic member mounting seat is installed at the top of the sand-discharging nozzle seat; one end of the elastic member is installed on the elastic member mounting seat, and the other end is connected to the pressing seat installed on the top end of the needle rod, and the air outlet on the sand-discharging nozzle is cleaned by operating the pressing seat to drive the needle rod to move; the pressing seat is located on the outside of the main valve body.

[0012] Preferably, the sand channel assembly further includes a fourth sand channel and a fifth sand channel, the central axis of the first sand channel being arranged in a vertical direction; the bottom end of the first sand channel is connected with the second sand channel through the fourth sand channel; the outlet of the second sand channel is connected with the third sand channel whose centerline axis is inclined downward through the fifth sand channel arranged vertically with the centerline axis; the offset distance Y between the centerline axis of the first sand channel and the centerline axis of the second sand channel in the horizontal plane is 10-20mm; the offset distance X between the top end surface at the connection between the second sand channel and the fifth sand channel and the bottom end surface at the connection between the third sand channel and the fifth sand channel in the vertical plane is 10-15mm.

[0013] Preferably, both ends of the second sand channel are closed by a sand pushing cap seat, an air flow cap and a baffle cleaning seat;

[0014] The baffle cleaning seat is used to open the second sand path horizontally, and is used to clean the impurities mixed in the second sand path; the distance between the baffle cleaning seat and the central axis of the second sand path is 30-40mm;

[0015] The airflow cap is installed on the second sand channel through a sand pushing cap seat. The airflow through the second air channel blows out compressed air after passing through the airflow cap, which is used to drive the sand particles flowing into the second sand channel to flow forward into the third sand channel.

[0016] Preferably, the airflow cap comprises a hollow column and a core structure arranged in the column, and the core structure is a sheet or plate structure with micropores.

[0017] Preferably, a sand spreading amount adjustment mechanism is further provided on the main valve body, and the sand spreading amount adjustment mechanism comprises an adjustment column, and the adjustment column is used to adjust the size of the airflow passing through the airflow cap.

[0018] Preferably, the air inlet assembly also includes a filter assembly, which includes a filter mounting seat and a filter, and the filter is arranged in the air inlet body through the filter mounting seat; the filter is a hollow cylindrical structure with a cavity, and the main air inlet joint is connected to the cavity of the filter, so that the air entering from the main air inlet joint passes through the filter and then smoothly enters the airflow cap and flows out.

[0019] Preferably, a sand blocking plug and a sand blocking cover are detachably provided at the sand discharge port, and a part of the sand blocking plug can be inserted into the sand discharge port; the sand blocking cover is arranged on the outside of the sand blocking plug to completely seal the sand discharge port.

[0020] The application of the technical solution of the present invention has the following beneficial effects:

[0021] (1) The gravity-type sand-spreading valve of the present invention comprises a main valve body, on which a sand inlet, a sand channel assembly, a sand outlet head, an air inlet assembly, an air duct assembly and a sand-blowing assembly are arranged. The air inlet assembly comprises an air inlet body, a main air inlet joint and a sand outlet nozzle seat. The sand outlet nozzle seat is detachably arranged on the air inlet body and a sand-blowing assembly is arranged on the sand outlet nozzle seat. The sand-blowing assembly comprises a mounting seat, a needle rod, an elastic member and a sand outlet nozzle. In the prior art, the sand outlet nozzle on the sand-spreading valve blows out the stirred sand particles. Although blockage rarely occurs during actual use, if the air duct of the nozzle is blocked by sand particles, the conventional method is to disassemble the sand outlet nozzle, then clear the air duct with wire or other needle-shaped objects, and finally reassemble it. This process is time-consuming and labor-intensive. The present invention modularizes the sand-blowing assembly and presses the needle rod to insert it into the air duct of the sand outlet nozzle to clear it, so as to achieve a quick and effective cleaning effect and greatly improve the sand-spreading efficiency.

[0022] (2) The air inlet body of the present invention is provided with a tapered mounting hole that is wide at the top and narrow at the bottom, and an internal thread is provided in the tapered mounting hole; the lower end of the sand outlet nozzle seat is a tapered body that matches the tapered mounting hole, and the outer wall of the tapered body is provided with an external thread that matches the internal thread. The present invention adopts an external structure for the sand blowing component to facilitate disassembly and maintenance; when the sand blowing component needs to be taken out as a whole for maintenance, sand or dust will inevitably be brought out. The present invention adopts the form of conical surface docking, which, on the one hand, ensures that sand or dust will not easily fall into the countersunk hole on the end face, and on the other hand, ensures that the sand or dust that falls in will flow out along the inclined surface by itself to avoid pollution.

[0023] (3) The sand channel assembly of the present invention further comprises a fourth sand channel and a fifth sand channel, wherein the central axis of the first sand channel is arranged in the vertical direction; the bottom end of the first sand channel is connected with the second sand channel through the fourth sand channel; the outlet of the second sand channel is connected with the third sand channel whose centerline axis is arranged obliquely downward through the fifth sand channel arranged vertically with the centerline axis; the offset distance Z between the centerline axis of the first sand channel and the centerline axis of the second sand channel in the horizontal plane is 10-20 mm; the offset distance X between the centerline axis of the second sand channel and the centerline axis of the third sand channel in the vertical plane is 10-15 mm. The present invention adopts a combination design of five sand channels. Since the sand particles flow directly downward through the first sand channel, the weight of the sand particles accumulated in the first sand channel is all concentrated at the bottom of the first sand channel. At this time, the airflow blows up the sand particles flowing into this place. If the second sand channel is directly intersected with the first sand channel vertically, it is possible that the ejected compressed air cannot blow up the sand particles or the sand particles are blown by the breath, resulting in unstable sand spreading. Therefore, the second sand channel is offset so that the gravity of the sand particles acts on the bottom of the first sand channel and then flows to the second sand channel through the fourth sand channel by its own weight. At this time, the airflow only needs to blow up part of the sand particles flowing into the second sand channel, thereby improving the stability of sand spreading. The top surface of the connection between the second sand channel and the fifth sand channel is 10-15mm away from the bottom surface of the connection between the third sand channel and the fifth sand channel in the vertical plane. This drop prevents the sand particles left in the second sand channel from the first sand channel from overflowing from the third sand channel due to vibration during the operation of the rail vehicle.

[0024] (4) The two ends of the second sand channel in the present invention are closed by a sand pushing cap seat, an air flow cap and a baffle cleaning seat. The sand stirring air nozzles on the original sand spreading valves are all installed downwards, and their function is to stir the sand particles in the sand chamber. Due to direct contact with the raised sand particles, blockage often occurs, resulting in poor sand spreading, and it needs to be disassembled for maintenance. In addition, the high-speed air flow vertically sprays the sand chamber surface, which will cause great impact and wear on it. Therefore, the present invention adopts an air flow cap design, which can only allow gas to pass through, while retaining the sand particles on the outer surface of the permeable sheet. With the input of compressed air from the main air inlet joint, even the dust attached to the outer surface of the sintering plate will be discharged with the compressed air, which is equivalent to a self-cleaning without blockage. And after the gas passes through the air flow cap, the compressed air will be dispersed while the pressure is reduced, so that the injection force is very small, avoiding the impact and wear of direct injection on the accessories.

[0025] (5) The main valve body of the present invention is also provided with a sand spreading amount adjustment mechanism, which includes an adjustment column, and the adjustment column is used to adjust the size of the airflow passing through the airflow cap. The existing sand spreading valve adjusts the sand spreading amount by changing the total air intake. The sand spreading nozzle and the sand stirring nozzle in the sand spreading valve are input through the same air duct. When the sand spreading amount is required to be small, the air volume will be reduced accordingly. At this time, due to the limited amount of air blown out, the sand particles carried by it will be parabolically ejected onto the rail surface, rather than directly sprayed between the wedge angle of the rail and the wheelset, resulting in low sand spreading efficiency. The present invention designs the sand spreading amount adjustment mechanism to change the air duct leading to the air flow cap. When the total air intake is at the rated value, the high-pressure air directly passes through the sand outlet nozzle to ensure the strength of sand blowing. By adjusting the air volume at the sand turning nozzle, the amount of sand blown up can be controlled, and the sand spreading amount can be adjusted. Finally, the airflow blown out of the sand outlet nozzle sprays sand particles at high speed between the wedge angle of the rail and the wheelset, thereby improving the sand spreading efficiency.

[0026] (6) The air inlet assembly of the present invention also includes a filter assembly, which includes a filter mounting seat and a filter. The design of the filter assembly can ensure that sufficient compressed air enters the airflow cap, and can also block impurities in the air to prevent pollution of the air duct. The sand discharge port is detachably provided with a sand plug and a sand plug cover. When the sand plug and the sand plug cover are opened, large particles of impurities can be cleaned and flow out along the first sand channel. When the sand plug and the sand plug cover are closed, the sand particles can be prevented from continuing to flow out.

[0027] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 It is a structural schematic diagram of a gravity-type sand spreading valve in a preferred embodiment of the present invention;

[0030] Figure 2 yes Figure 1 AA section view;

[0031] Figure 3 yes Figure 2 A partial enlarged view of the

[0032] Figure 4 yes Figure 1 CC section view;

[0033] Figure 5 yes Figure 1A schematic diagram of the structure from another perspective;

[0034] Figure 6 yes Figure 5 BB cross-sectional view;

[0035] Figure 7 yes Figure 1 D-direction view;

[0036] Among them, 1. Main valve body; 2. Sand inlet; 3. Sand channel assembly, 3.1. First sand channel, 3.2. Second sand channel, 3.3. Third sand channel, 3.4. Fourth sand channel, 3.5. Fifth sand channel; 4. Sand outlet; 5. Air inlet assembly, 5.1. Air inlet body, 5.2. Total air inlet joint, 5.3. Sand outlet nozzle seat, 5.4. Filter assembly, 5.4.1. Filter mounting seat, 5.4.2. Filter; 6. Air duct assembly, 6.1. First air duct, 6.2. Second air duct, 6.3. Third air duct, 6.4. Fourth air duct, 6.5. Fifth air duct, 6.6. Sixth air duct, 6.7, seventh air duct, 6.8, eighth air duct, 6.9, ninth air duct, 6.10, tenth air duct, 6.11, eleventh air duct, 6.12, twelfth air duct, 6.13, thirteenth air duct, 6.14, fourteenth air duct, 6.15, fifteenth air duct; 7, sand blowing assembly, 7.1, pressing seat, 7.2, needle rod, 7.3, elastic part, 7.4, sand outlet nozzle, 7.5, elastic part mounting seat; 8, sand pushing cap seat; 9, air flow cap; 10, baffle cleaning seat; 11, adjusting column; 12, sand blocking plug; 13, sand blocking cover; 14, plug. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0038] Example:

[0039] A gravity sand spreading valve is installed at the outlet of the lower part of a sand box, and the sand box can be various sand boxes in the prior art.

[0040] The gravity-type sand spreading valve of this embodiment comprises a main valve body 1, on which a sand inlet 2, a sand channel assembly 3, a sand outlet head 4, an air inlet assembly 5, an air channel assembly 6 and a sand blowing assembly 7 are arranged. Figure 1-Figure 7 , the detailed structure is as follows:

[0041] The main valve body 1 is internally processed with a sand channel component 3 for the flow of sand particles. Figure 2 , Figure 4 , Figure 6 and Figure 7The sand channel assembly 3 includes a first sand channel 3.1, a second sand channel 3.2, a third sand channel 3.3, a fourth sand channel 3.4 and a fifth sand channel 3.5. One end of the first sand channel 3.1 is connected to the sand inlet 2, and the other end of the first sand channel 3.1 is connected to the entrance of the third sand channel 3.3 arranged in the sand outlet head 4 through the fourth sand channel 3.4, the second sand channel 3.2 and the fifth sand channel 3.5. The outlet of the third sand channel 3.3 is connected to the sand outlet in the sand outlet head 4; a sand discharge port is provided at the bottom of the first sand channel 3.1. Preferably, the center axis of the first sand path 3.1 is arranged in the vertical direction; the bottom end of the first sand path 3.1 is connected to the second sand path 3.2 through the fourth sand path 3.4; the outlet of the second sand path 3.2 is connected to the third sand path 3.3 with the center axis tilted downward through the fifth sand path 3.5 arranged vertically with the center axis; the offset distance Z between the center axis of the first sand path 3.1 and the center axis of the second sand path 3.2 in the horizontal plane is 10-20mm; the top end surface of the connection between the second sand path 3.2 and the fifth sand path is 10-15mm away from the bottom end surface of the connection between the third sand path 3.3 and the fifth sand path in the vertical plane. This drop prevents the sand particles flowing from the first sand path into the second sand path from overflowing from the third sand path due to vibration during the operation of the rail vehicle. It is further preferred that the center axes of the second sand path and the fourth sand path are arranged tilted downward along the direction of the sand particles.

[0042] The air inlet assembly 5 includes an air inlet body 5.1, a main air inlet joint 5.2 and a sand outlet nozzle seat 5.3, see Figure 2 and Figure 3The sand outlet nozzle seat 5.3 is detachably arranged on the air inlet body 5.1 and a sand blowing assembly is arranged on the sand outlet nozzle seat 5.3. The sand blowing assembly 7 comprises a pressing seat 7.1, a needle rod 7.2, an elastic member 7.3 (preferably a spring), a sand outlet nozzle 7.4 and an elastic member mounting seat 7.5 (preferably a positioning spring seat). The sand outlet nozzle 7.4 is fixedly arranged at the front end of the sand outlet nozzle seat 5.3 and provides power for blowing out the sand particles in the sand outlet head 4. The needle rod 7.2 is movably arranged relative to the sand outlet nozzle 7.4 through the elastic member 7.3 and the air outlet on the sand outlet nozzle 7.4 is cleaned by controlling the movement of the needle rod. The needle rod 7.2 passes through the hole in the sand outlet nozzle seat 5.3 until the end face of the sand outlet nozzle 7.4, and the needle rod 7.2 is close to the sand outlet nozzle 7. The front end of the needle 4 is in the shape of a needle head, and its outer diameter is smaller than the air outlet on the sand outlet nozzle 7.4; the elastic member mounting seat 7.5 is installed on the top of the sand outlet nozzle seat 5.3; one end of the elastic member 7.3 is installed on the elastic member mounting seat 7.5, and the other end is installed on the pressing seat 7.1 at the top of the needle bar 7.2. The spring forms a pulling force through the sealing ring fixing step at the middle and rear part of the needle bar and the limit of the pressing seat, so that the sealing ring fixing step at the middle and rear part of the needle bar is pressed tightly against the bottom of the positioning spring seat, and the sealing ring installed thereon is sealed. The sealing ring fixing step at the middle and rear part of the needle bar can also play a limiting role, so that it is positioned at the bottom of the spring seat. By operating the pressing seat 7.1, the needle bar is driven to move to realize the cleaning of the air outlet on the sand outlet nozzle 7.4, and after releasing the pressing seat, the needle bar returns to its original position driven by the spring. The pressing seat 7.1 is located on the outside of the main valve body 1. In this embodiment, the air inlet body 5.1 is preferably provided with a tapered mounting hole that is wide at the top and narrow at the bottom, and an internal thread is provided in the tapered mounting hole; the lower end of the sand outlet nozzle seat 5.3 is a tapered body that matches the tapered mounting hole, and an external thread that matches the internal thread is provided on the outer wall of the tapered body. The sand outlet nozzle, the sand outlet head and the third sand channel are coaxially inclined straight-through structures, and since there is no pipe bend, efficient airflow transmission can be achieved, while avoiding wear on the pipe wall.

[0043] In this embodiment, the air inlet assembly further includes a filter assembly 5.4, and the filter assembly 5.4 includes a filter mounting seat 5.4.1 and a filter 5.4.2, see Figure 2 and Figure 3The filter 5.4.2 is arranged in the air inlet body 5.1 through the filter mounting seat 5.4.1; the filter 5.4.2 is a hollow columnar structure with a cavity, and the main air inlet joint 5.2 is connected with the cavity of the filter 5.4.2, so that the air entering from the main air inlet joint 5.2 passes through the filter 5.4.2 and then flows out smoothly into the airflow cap 9. Further preferably, the filter is made of plastic and has a notch at its front end. The diameter of the inner hole of the filter is smaller than the outer diameter of the cylindrical boss of the inserted filter seat. Because the filter has a notch, the filter can be inserted into the cylindrical boss of the filter mounting seat and tightly wrapped when the notch is opened. Since the plastic has a certain flexibility, it can not only ensure that the filter can be tightly attached to the filter mounting seat, but also prevent it from being torn. A filter screen with a length of 10 to 15 mm and a pore size of 0.1×0.1 is designed on both sides of the middle part of the filter mounting seat to ensure that sufficient compressed air can enter and impurities can be blocked to prevent pollution of the air duct. The rear end of the filter is a closed structure and is designed with a protruding flat mouth, which can be clamped by tools to plug and unplug the filter.

[0044] Preferably, in this embodiment, both ends of the second sand channel 3.2 are closed by a sand pushing cap seat 8, an air flow cap 9 and a baffle cleaning seat 10, see Figure 6 ; The baffle cleaning seat 10 is used to open the second sand channel 3.2 laterally, and is used to clean the impurities mixed in the second sand channel; the distance between the baffle cleaning seat 10 and the central axis of the second sand channel 3.2 is 30-40mm. At this distance, when the baffle cleaning seat is opened, the sand stored in the third sand channel will not automatically flow out due to its own stacking angle, which is convenient for cleaning; the airflow cap 9 is installed on the second sand channel 3.2 by pushing the sand cap seat 8, and the compressed air is blown out after the airflow passes through the airflow cap 9, which is used to drive the sand flowing into the second sand channel 3.2 to flow forward into the third sand channel 3.3. It is further preferred here that: the airflow cap 9 includes a hollow column and a core structure arranged in the column, and the core structure is a sheet or plate structure with micropores. The airflow cap is coaxially placed horizontally with the second sand channel. The compressed air blown out by the airflow cap drives the sand particles flowing into the second sand channel to flow forward. At this time, the sand outlet nozzle blows out a high-speed airflow, resulting in a small internal pressure of the airflow, while the external flow rate is slow and the pressure is large. The pressure difference causes the airflow to "suck" up the sand particles blown by the airflow cap in the second sand channel, and blow the sucked sand particles out from the third sand channel to achieve the purpose of sand spreading.

[0045] Preferably, in this embodiment, a sand spreading amount adjustment mechanism is further provided on the main valve body 1 , and the sand spreading amount adjustment mechanism includes an adjustment column 11 , and the adjustment column 11 is used to adjust the size of the airflow passing through the airflow cap 9 .

[0046] The main valve body is processed with a compressed air flow channel air duct component 6, see Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6 The air duct assembly 6 includes a first air duct 6.1, a second air duct 6.2, a third air duct 6.3, a fourth air duct 6.4, a fifth air duct 6.5, a sixth air duct 6.6, a seventh air duct 6.7, an eighth air duct 6.8, a ninth air duct 6.9, a tenth air duct 6.10, an eleventh air duct 6.11, a twelfth air duct 6.12, a thirteenth air duct 6.13, a fourteenth air duct 6.14 and a fifteenth air duct 6.15. The first air duct 6.1 is connected to the total air inlet joint 5.2 and the third sand channel 3.3 in the sand outlet head 4, and is used to blow out the sand in the sand outlet head; the second air duct 6.2 is connected to the total air inlet joint 5.2 and the second sand channel 3.2, and is used to blow the sand in the second sand channel 3.2 into the third sand channel 3.3. The specific structure is as follows:

[0047] The first air duct 6.1 is provided at the part where the first channel 5.1.1 is connected to the main air inlet joint 5.2; the cavity located at the periphery of the filter forms the second air duct 6.2, and the cavity of the filter forms the third air duct 6.3; the sand outlet air nozzle seat 5.3 is T-shaped, and the middle part is designed as a conical surface, and the cone angle Y is between 15° and 25°, see Figure 3 A sealing groove is designed on the conical surface to place a sealing ring, which is sealed by fitting with the conical inner hole of the air inlet body 5.1. An annular circular groove is opened at the rear end of the conical surface of the sand outlet nozzle seat 5.3 to form the fifth air duct 6.5, and a through hole penetrating the two ends of the circular groove is processed at the center of the circular groove to form the sixth air duct 6.6; the circular rod in the middle of the needle rod 7.2 and the countersunk hole and inner hole in the middle of the sand outlet nozzle seat 5.3 form the seventh air duct 6.7 and the eighth air duct 6.8 connected in sequence, and the eighth air duct 6.8 is connected to the sand outlet nozzle 7.4; the second air duct 6.2 is connected to the seventh air duct 6.7 through the fourth air duct 6.4, the fifth air duct 6.5 and the sixth air duct 6.6 connected in sequence; the third air duct 6.3 conveys airflow to the second sand channel 3.2 through the ninth air duct 6.9 and the tenth air duct 6.10 arranged in sequence.

[0048] The adjustment column 11 is a cylindrical structure, with an inner hexagonal groove on its outer end face, and a blind hole coaxial with the tenth air duct 6.10 on the other end face to form the eleventh air duct 6.11, the depth of the blind hole is just the intersection with the thirteenth air duct 6.13, and a through circular hole coaxial with the thirteenth air duct 6.13 is opened at the bottom of the above circular hole to form the twelfth air duct 6.12. At this time, the ninth air duct 6.9 is connected to the thirteenth air duct 6.13 through the eleventh air duct 6.11 and the twelfth air duct 6.12 on the adjustment column 11, and the twelfth air duct 6.12 on the adjustment column 11 can be driven to rotate by rotating the inner hexagonal slot on the adjustment column 11, and the air volume is adjusted by changing the cross-sectional area of ​​the twelfth air duct 6.12; the twelfth air duct 6.12 is connected to the airflow cap 9 through the thirteenth air duct 6.13, the fourteenth air duct 6.14 and the fifteenth air duct 6.15 connected in sequence; the fourteenth air duct is closed by the sand pushing cap seat 8 and the plug 14.

[0049] In this embodiment, preferably, a sand plug 12 and a sand plugging cover 13 are detachably provided at the sand discharge port, and a part of the sand plug 12 can be inserted into the sand discharge port; the sand plugging cover 13 is arranged on the outside of the sand plug 12, and is used to completely close the sand discharge port. Specifically: the sand plug is designed to have a cylindrical head at one end and a flat structure at the other end. When the sand plug and the sand plugging cover are opened, large particles of impurities can be cleaned and flow out along the first sand channel. After cleaning, one end of the cylindrical head of the sand plug can be inserted upward into the first sand channel. Since the outer diameter of the top cylindrical head of the sand plug is slightly smaller than the inner diameter of the first sand channel, the friction force formed by the sand particles stuck in the gap when the sand particles flow down during the upward insertion process can be used to block the sand plug tightly on the first sand channel to prevent the sand particles from continuing to flow out, and then the sand plugging cover is installed to seal it.

[0050] The specific scheme of applying this embodiment is as follows:

[0051] The sand flow path is as follows:

[0052] The sand is stored in a sand box; the sand in the sand box enters the sand inlet 2 in the main valve body 1 of the gravity sand spreading valve through the outlet at the bottom of the sand box; the sand through the sand inlet 2 falls into the first sand channel 3.1, and under the gravity of the sand, the sand enters the fourth sand channel 3.4 and falls into the second sand channel 3.2; under the action of the airflow ejected by the airflow cap 9, the sand in the second sand channel 3.2 is blown into the inclined third sand channel 3.3 through the fifth sand channel 3.5, and then ejected from the sand outlet head 4 at high speed under the action of the airflow of the sand outlet nozzle 7.4.

[0053] The air flow path is as follows:

[0054] The airflow entering through the main air inlet connector 5.2 in the air inlet assembly 5 enters the first air duct 6.1 and is divided into two paths, as follows:

[0055] First airflow: After entering the second airflow 6.2 through the first airflow 6.1, the airflow passes through the fourth airflow 6.4, the fifth airflow 6.5, the sixth airflow 6.6, the seventh airflow 6.7 and the eighth airflow 6.8 in sequence and is connected to the sand outlet nozzle 7.4, providing power for the sand to be ejected from the sand outlet head 4 at high speed.

[0056] Second airflow: the gas passes through the first air duct 6.1 and then enters the third air duct 6.3 through the filter tip. The airflow passes through the third air duct 6.3, the ninth air duct 6.9, the tenth air duct 6.10, the eleventh air duct 6.11, the twelfth air duct 6.12, the thirteenth air duct 6.13, the fourteenth air duct 6.14 and the fifteenth air duct 6.15 in sequence and then is connected with the airflow cap, providing power for the sand in the second sand channel 3.2 to be blown into the inclined third sand channel 3.3 through the fifth sand channel 3.5.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gravity sand spreading valve, characterized in that: It comprises a main valve body (1), wherein the main valve body (1) is provided with a sand inlet (2), a sand channel assembly (3), a sand outlet head (4), an air inlet assembly (5), an air channel assembly (6), and a sand blowing assembly (7); The sand channel assembly (3) comprises a first sand channel (3.1), a second sand channel (3.2) and a third sand channel (3.3) which are connected in sequence; one end of the first sand channel (3.1) is connected to a sand inlet (2); the other end of the first sand channel (3.1) is connected to an inlet of a third sand channel (3.3) provided in a sand outlet head (4) through the second sand channel (3.2); and the outlet of the third sand channel (3.3) is connected to a sand outlet in the sand outlet head (4); a sand outlet is provided at the bottom of the first sand channel (3.1); The air inlet assembly (5) comprises an air inlet body (5.1), a main air inlet joint (5.2) and a sand outlet nozzle seat (5.3) arranged on the air inlet body (5.1); the sand outlet nozzle seat (5.3) is a columnar structure with a hollow channel, and the sand outlet nozzle seat (5.3) is detachably arranged on the air inlet body (5.1); a sand blowing assembly (7) is provided on the sand outlet nozzle seat (5.3), and the sand blowing assembly (7) comprises a needle rod (7.2), an elastic member (7.3) and a sand outlet nozzle (7.4); the sand outlet nozzle (7.4) is arranged on the sand outlet nozzle seat (5.3) and can provide power for blowing out sand particles in the sand outlet head (4); the needle rod (7.2) is inserted into the hollow channel and is movably arranged relative to the sand outlet nozzle (7.4) through the elastic member (7.3), and the air outlet on the sand outlet nozzle (7.4) is cleaned by controlling the movement of the needle rod; The air duct assembly (6) comprises a first air duct (6.1) and a second air duct (6.2); the first air duct (6.1) is connected to the main air inlet joint (5.2) and the third sand channel (3.3) in the sand outlet head (4), and is used for blowing out sand particles in the sand outlet head; the second air duct (6.2) is connected to the main air inlet joint (5.2) and the second sand channel (3.2), and is used for blowing sand particles in the second sand channel (3.2) into the third sand channel (3.3).

2. The gravity-type sand spreading valve according to claim 1, characterized in that: The air inlet body (5.1) is provided with a tapered mounting hole which is wide at the top and narrow at the bottom, and an internal thread is provided in the tapered mounting hole; the sand discharge nozzle seat (5.3) is a tapered body which matches the tapered mounting hole, and an external thread which matches the internal thread is provided on the outer wall of the tapered body.

3. The gravity-type sand spreading valve according to claim 1, characterized in that: The sand-discharging assembly further comprises a pressing seat (7.1) and an elastic member mounting seat (7.5); the sand-discharging nozzle (7.4) is mounted on the bottom end of the sand-discharging nozzle seat (5.3); the needle rod (7.2) is inserted into the hollow passage in the sand-discharging nozzle seat (5.3) until it reaches the end face of the sand-discharging nozzle (7.4); the front end of the needle rod (7.2) close to the sand-discharging nozzle (7.4) is in the shape of a needle head, and its outer diameter is smaller than the air outlet on the sand-discharging nozzle (7.4); An elastic member mounting seat (7.5) is mounted on the top of the sand outlet nozzle seat (5.3); one end of the elastic member (7.3) is mounted on the elastic member mounting seat (7.5), and the other end is connected to a pressing seat (7.1) mounted on the top of the needle rod (7.2); the pressing seat (7.1) is operated to drive the needle rod to move, thereby cleaning the air outlet on the sand outlet nozzle (7.4); the pressing seat (7.1) is located outside the main valve body (1).

4. The gravity-type sand spreading valve according to claim 1, characterized in that: The sand channel assembly (3) further comprises a fourth sand channel (3.4) and a fifth sand channel (3.5), wherein the central axis of the first sand channel (3.1) is arranged in a vertical direction; the bottom end of the first sand channel (3.1) is connected to the second sand channel (3.2) via the fourth sand channel (3.4); the outlet of the second sand channel (3.2) is connected to the third sand channel (3.3) with its centerline axis tilted downward via the fifth sand channel (3.5) arranged vertically with its centerline axis; the offset distance Z between the centerline axis of the first sand channel (3.1) and the centerline axis of the second sand channel (3.2) in the horizontal plane is 10-20 mm; the offset distance X between the top end surface at the connection point of the second sand channel (3.2) and the fifth sand channel (3.5) and the bottom end surface at the connection point of the third sand channel (3.3) and the fifth sand channel (3.5) in the vertical plane is 10-15 mm.

5. The gravity-type sand spreading valve according to claim 1, characterized in that: Both ends of the second sand channel (3.2) are sealed by a sand pushing cap seat (8), an air flow cap (9) and a baffle cleaning seat (10); The baffle cleaning seat (10) is used to open the second sand channel (3.2) laterally and to clean impurities mixed in the second sand channel; the distance between the baffle cleaning seat (10) and the central axis of the second sand channel (3.2) is 30-40 mm; The airflow cap (9) is installed on the second sand channel (3.2) through the sand cap pusher (8). The airflow through the second air duct (6.2) blows out compressed air after passing through the airflow cap (9), which is used to drive the sand particles flowing into the second sand channel (3.2) to flow forward into the third sand channel (3.3).

6. The gravity-type sand spreading valve according to claim 5, characterized in that: The airflow cap (9) comprises a hollow column and a core structure arranged in the column, wherein the core structure is a sheet-like or plate-like structure with micropores.

7. The gravity-type sand spreading valve according to claim 5, characterized in that: The main valve body (1) is also provided with a sand spreading amount adjustment mechanism, which comprises an adjustment column (11). The adjustment column (11) is used to adjust the size of the airflow passing through the airflow cap (9).

8. The gravity-type sand spreading valve according to claim 5, characterized in that: The air inlet assembly (5) further comprises a filter assembly (5.4), the filter assembly (5.4) comprising a filter mounting seat (5.4.1) and a filter (5.4.2), the filter (5.4.2) being arranged in the air inlet body (5.1) via the filter mounting seat (5.4.1); the filter (5.4.2) being a hollow columnar structure having a cavity, the main air inlet joint (5.2) being in communication with the cavity of the filter (5.4.2), so that the air entering through the main air inlet joint (5.2) passes through the filter (5.4.2) and smoothly enters the airflow cap (9) and flows out.

9. The gravity-type sand spreading valve according to any one of claims 1 to 8, characterized in that: The sand discharge port is detachably provided with a sand blocking plug (12) and a sand blocking cover (13), wherein a portion of the sand blocking plug (12) can be inserted into the sand discharge port; and the sand blocking cover (13) is arranged on the outside of the sand blocking plug (12) and is used to completely seal the sand discharge port.

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